Buggy code:
protected static final int MAX_FRAME_DEPTH = JMeterUtils . getPropDefault ( "httpsampler.max_frame_depth" , 5 ) ; private static final Map < String , String > parsersForType = new HashMap < String , String > ( ) ; private static final String RESPONSE_PARSERS = JMeterUtils . getProperty ( "HTTPResponse.parsers" ) ; private static boolean REMOVESLASHDOTDOT = JMeterUtils . getPropDefault ( "httpsampler.redirect.removeslashdotdot" , true ) ; private boolean dynamicPath = false ; public HTTPSamplerBase ( ) { } public boolean getSendFileAsPostBody ( ) { } public boolean getSendParameterValuesAsPostBody ( ) { } public boolean getUseMultipartForPost ( ) { } public void setProtocol ( String value ) { } public String getProtocol ( ) { } public void setPath ( String path ) { } public void setPath ( String path , String contentEncoding ) { } public String getPath ( ) { } public void setFollowRedirects ( boolean value ) { } public boolean getFollowRedirects ( ) { } public void setAutoRedirects ( boolean value ) { } public boolean getAutoRedirects ( ) { } public void setMethod ( String value ) { } public String getMethod ( ) { } public void setContentEncoding ( String value ) { } public String getContentEncoding ( ) { } public void setUseKeepAlive ( boolean value ) { } public boolean getUseKeepAlive ( ) { } public void setDoMultipartPost ( boolean value ) { } public boolean getDoMultipartPost ( ) { } public void setDoBrowserCompatibleMultipart ( boolean value ) { } public boolean getDoBrowserCompatibleMultipart ( ) { } public void setMonitor ( String value ) { } public void setMonitor ( boolean truth ) { } public String getMonitor ( ) { } public boolean isMonitor ( ) { } public void setImplementation ( String value ) { } public String getImplementation ( ) { } public boolean useMD5 ( ) { } public void setMD5 ( boolean truth ) { } public void addEncodedArgument ( String name , String value ) { } public void addEncodedArgument ( String name , String value , String metaData , String contentEncoding ) { } public void addEncodedArgument ( String name , String value , String metaData ) { } public void addNonEncodedArgument ( String name , String value , String metadata ) { } public void addArgument ( String name , String value ) { } public void addArgument ( String name , String value , String metadata ) { } public boolean hasArguments ( ) { } @ Override public void addTestElement ( TestElement el ) { } @ Override public void clearTestElementChildren ( ) { } public void setPort ( int value ) { } public static int getDefaultPort ( String protocol , int port ) { } public int getPortIfSpecified ( ) { } public boolean isProtocolDefaultPort ( ) { } public int getPort ( ) { } public void setDomain ( String value ) { } public String getDomain ( ) { } public void setConnectTimeout ( String value ) { } public int getConnectTimeout ( ) { } public void setResponseTimeout ( String value ) { } public int getResponseTimeout ( ) { } public String getProxyHost ( ) { } public int getProxyPortInt ( ) { } public String getProxyUser ( ) { } public String getProxyPass ( ) { } public void setArguments ( Arguments value ) { } public Arguments getArguments ( ) { } public void setAuthManager ( AuthManager value ) { } public AuthManager getAuthManager ( ) { } public void setHeaderManager ( HeaderManager value ) { HeaderManager mgr = getHeaderManager ( ) ; if ( mgr != null ) { <START_BUG> HTTPSamplerBase . log . warn ( ( ( ( ( "Existing<seq2seq4repair_space>HeaderManager<seq2seq4repair_space>'" + ( mgr . getName ( ) ) ) + "'<seq2seq4repair_space>merged<seq2seq4repair_space>with<seq2seq4repair_space>'" ) + ( value . getName ( ) ) ) + "'" ) ) ; <END_BUG> value = mgr . merge ( value , true ) ; if ( HTTPSamplerBase . log . isDebugEnabled ( ) ) { HTTPSamplerBase . log . debug ( ( "HeaderManager<seq2seq4repair_space>merged:<seq2seq4repair_space>" + ( value . getName ( ) ) ) ) ; for ( int i = 0 ; i < ( value . getHeaders ( ) . size ( ) ) ; i ++ ) { HTTPSamplerBase . log . debug ( ( ( ( "<seq2seq4repair_space>" + ( value . getHeader ( i ) . getName ( ) ) ) + "=" ) + ( value . getHeader ( i ) . getValue ( ) ) ) ) ; } } } setProperty ( new org . apache . jmeter . testelement . property . TestElementProperty ( HTTPSamplerBase . HEADER_MANAGER , value ) ) ; } public HeaderManager getHeaderManager ( ) { } public void setCookieManager ( CookieManager value ) { } public CookieManager getCookieManager ( ) { } public void setCacheManager ( CacheManager value ) { } public CacheManager getCacheManager ( ) { } public boolean isImageParser ( ) { } public void setImageParser ( boolean parseImages ) { } public String getEmbeddedUrlRE ( ) { } public void setEmbeddedUrlRE ( String regex ) { } protected HTTPSampleResult errorResult ( Throwable e , HTTPSampleResult res ) { } private static final String HTTP_PREFIX = ( PROTOCOL_HTTP ) + ":////" ; private static final String HTTPS_PREFIX = ( PROTOCOL_HTTPS ) + ":////" ; public java . net . URL getUrl ( ) throws MalformedURLException { } public String getQueryString ( ) { } public String getQueryString ( String contentEncoding ) { } public void parseArguments ( String queryString , String contentEncoding ) { } public void parseArguments ( String queryString ) { } @ Override public String toString ( ) { } public SampleResult sample ( Entry e ) { } public SampleResult sample ( ) { } private HTTPSampleResult fileSample ( URI uri ) throws IOException { } protected abstract HTTPSampleResult sample ( java . net . URL u , String method , boolean areFollowingRedirect , int depth ) { }

Fix:
HTTPSamplerBase . log . debug ( ( ( ( ( "Existing<seq2seq4repair_space>HeaderManager<seq2seq4repair_space>'" + ( mgr . getName ( ) ) ) + "'<seq2seq4repair_space>merged<seq2seq4repair_space>with<seq2seq4repair_space>'" ) + ( value . getName ( ) ) ) + "'" ) ) ;